Alfa-Romeo 156 Top Speed: The Alfa-Romeo 156 2.5 V6 - [1997] has a top speed of 143 mph (230.1 kph) Alfa-Romeo 156 Acceleration: This 156 accelerates 0-60mph (96.6 kph) in 7.1 seconds or 0-100kph in 7.3 and can achieve an estimated 1/4 mile drag time in 15.28 seconds with a trap speed of 89.5 mph.